<?php

declare(strict_types=1);

namespace DoctrineMigrations;

use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;

final class Version20260227120500 extends AbstractMigration
{
    public function getDescription(): string
    {
        return 'Add external source columns (external_id, external_track_id) and OAuth identity fields on users';
    }

    public function up(Schema $schema): void
    {
        if ($this->shouldAddColumn($schema, 'albums', 'external_id')) {
            $this->addSql('ALTER TABLE albums ADD external_id VARCHAR(64) DEFAULT NULL');
        }

        if ($this->shouldAddColumn($schema, 'album_tracks', 'external_track_id')) {
            $this->addSql('ALTER TABLE album_tracks ADD external_track_id VARCHAR(64) DEFAULT NULL');
        }

        if ($this->shouldAddColumn($schema, 'users', 'oauth_provider')) {
            $this->addSql('ALTER TABLE users ADD oauth_provider VARCHAR(50) DEFAULT NULL');
        }

        if ($this->shouldAddColumn($schema, 'users', 'oauth_id')) {
            $this->addSql('ALTER TABLE users ADD oauth_id VARCHAR(190) DEFAULT NULL');
        }

        if ($this->hasColumn($schema, 'albums', 'spotify_id') && $this->hasColumn($schema, 'albums', 'external_id')) {
            $this->addSql('UPDATE albums SET external_id = spotify_id WHERE external_id IS NULL AND spotify_id IS NOT NULL');
        }

        if ($this->hasColumn($schema, 'albums', 'source')) {
            $this->addSql("UPDATE albums SET source = 'external' WHERE source = 'spotify'");
            if (!$this->isSqlite()) {
                $this->addSql("ALTER TABLE albums ALTER source SET DEFAULT 'external'");
            }
        }

        if ($this->hasColumn($schema, 'album_tracks', 'spotify_track_id') && $this->hasColumn($schema, 'album_tracks', 'external_track_id')) {
            $this->addSql('UPDATE album_tracks SET external_track_id = spotify_track_id WHERE external_track_id IS NULL AND spotify_track_id IS NOT NULL');
        }

        if (!$this->indexExists($schema, 'albums', 'uniq_album_external_id')) {
            $this->addSql('CREATE UNIQUE INDEX uniq_album_external_id ON albums (external_id)');
        }

        if (!$this->indexExists($schema, 'users', 'uniq_users_oauth_identity')) {
            $this->addSql('CREATE UNIQUE INDEX uniq_users_oauth_identity ON users (oauth_provider, oauth_id)');
        }
    }

    public function down(Schema $schema): void
    {
        if ($this->isSqlite()) {
            // SQLite column drops require table rebuilds; keep schema forward-only here.
            return;
        }

        if ($this->indexExists($schema, 'users', 'uniq_users_oauth_identity')) {
            $this->addSql('DROP INDEX uniq_users_oauth_identity');
        }

        if ($this->indexExists($schema, 'albums', 'uniq_album_external_id')) {
            $this->addSql('DROP INDEX uniq_album_external_id');
        }

        if ($this->hasColumn($schema, 'users', 'oauth_id')) {
            $this->addSql('ALTER TABLE users DROP COLUMN oauth_id');
        }

        if ($this->hasColumn($schema, 'users', 'oauth_provider')) {
            $this->addSql('ALTER TABLE users DROP COLUMN oauth_provider');
        }

        if ($this->hasColumn($schema, 'album_tracks', 'external_track_id')) {
            $this->addSql('ALTER TABLE album_tracks DROP COLUMN external_track_id');
        }

        if ($this->hasColumn($schema, 'albums', 'external_id')) {
            $this->addSql('ALTER TABLE albums DROP COLUMN external_id');
        }

        if ($this->hasColumn($schema, 'albums', 'source')) {
            $this->addSql("UPDATE albums SET source = 'spotify' WHERE source = 'external'");
            $this->addSql("ALTER TABLE albums ALTER source SET DEFAULT 'spotify'");
        }
    }

    private function shouldAddColumn(Schema $schema, string $tableName, string $columnName): bool
    {
        return $this->hasTable($schema, $tableName) && !$this->hasColumn($schema, $tableName, $columnName);
    }

    private function hasTable(Schema $schema, string $tableName): bool
    {
        return $schema->hasTable($tableName);
    }

    private function hasColumn(Schema $schema, string $tableName, string $columnName): bool
    {
        return $this->hasTable($schema, $tableName) && $schema->getTable($tableName)->hasColumn($columnName);
    }

    private function indexExists(Schema $schema, string $tableName, string $indexName): bool
    {
        return $this->hasTable($schema, $tableName) && $schema->getTable($tableName)->hasIndex($indexName);
    }

    private function isSqlite(): bool
    {
        return $this->connection->getDatabasePlatform()->getName() === 'sqlite';
    }
}